Terpolyamides useful in preparing textile fibers consisting essentially of nylon 66,nylon 6,and nylon 2-6ia



United States Patent 3,542,745 TERPOLYAMIDES USEFUL 1N PREPARING TEX-TILE FIBERS CONSISTING ESSENTIALLY OF NYLON 66, NYLON 6, AND NYLON 2-6IARupert J. Snooks, Jr., Gulf Breeze, Fla., assignor to Monsanto Company,St. Louis, Mo., a corporation of Delaware No Drawing. Filed Oct. 29,1968, Ser. No. 771,617 Int. Cl. 008g 20/12, 20/20 US. Cl. 260--78 9Claims ABSTRACT OF THE DISCLOSURE Textile fibers spun and drawn from asynthetic linear polyamide having a polymer chain consisting of at least93 weight percent 0 0 -NnoH2)u-Nn hcn, b units, from 0.25 to 3 weightpercent 0 NH(CH2)5&-

units and from 0.5 to 4 weight percent o 0 NH(CH2)NH( J J units in whichn is 2 to 6 are of improved quality and dyeability.

. BACKGROUND OF THE INVENTION -Nylon 66 (po yhexamethylene adipamide) iswell known for -its superior textile properties. However, it does havecertain disadvantages when used in providing textile yarns. Onedisadvantage is that when nylon 66 is processed into drawn yarn, theyarn tends to contain one or more short segments along its length whichhave a denier greater than that intended. These segments are flaws inthe yarn which result from defects in the polymer or from imperfectionsin the spinning operation. In knitting operations as the yarn passesthrough eyes of knitting machines such segments bind in the eyes causingthe yarn to break. The term internal quality has been coined to reflectthe number of these segments which exist along the length of the yarnand is deter mined by passing a sample of the yarn through a passagedefined by two pairs of parallel blades, one pair being positionedparallel above the other pair and at a 90 angle thereto, i.e., Thespacing between the parallel blades of each pair is set to permit yarnof a selected denier to pass through the passage defined by the bladeswithout obstruction. However, if the yarn contains segments of largerdenier, the blades cut the yarn. The number of cuts (breaks) in the yarnwhich occur in passing the yarn through the passage divided by thenumber of pounds of yarn involved is expressed as the internal quality(breaks per pound) of the yarn. In providing yarn for use in knittingoperations, the internal quality of theyam is of major concern.

' Another disadvantage in processing nylon 66 into textile yarns is thatfibers or fabrics prepared therefrom do not dye rapidly or uniformly.

An object of the present invention therefore is to provide a nylon yarnhaving physical properties comparable to nylon 66 as well as havingimproved internal quality, a high dye absorption rate and improveduniformity of dyeing.

3,542,745 Patented Nov. 24, 1970 SUMMARY OF THE INVENTION The above andother objects are accomplished by providing a textile filament spun anddrawn from a synthetic linear terpolyamide having a polymer chainconsisting of from about 93 to 99.25 weight percent of the repeatingunit -NH(oH2)flNHi 1 oH2)4 (66 units) from 0.25 to 3 weight percent ofthe repeating unit 0 NH(CHz) J (6 units) and from 0.5 to 4 weightpercent of the repeating unit in which n is 2 to 6, wherein said 66units, 6 units and nIA units are randomly distributed throughout saidpolymer chain.

The terpolyarnides may be prepared by polymerizing a mixture consistingof appropriate amounts of the terpolyamide-forming components in themanner well known in the art and commonly employed in the manufacture ofnylon 66. Thus, the terpolyarnides may be prepared according to amodified nylon 66 process wherein appropriate amounts of e-caprolactamand the selected diamine salt of isophthalic acid are added eitherseparately or in combination to the nylon 66 salt at any point in theprocess prior to polymerization.

The amount of e-caprolactam or e-amino-caproic acid used in forming theterpolyarnides preferably ranges from about 0.25 to 3 mole percent,based on the total weight of the terpolyamide-forming components.Although slightly greater amounts could possibly be used withoutaltering the character of the resulting terpolyamide, the improvement,if any, achieved thereby would be outweighed by cost considerations. Theamount of diamine-isophthalic acid salt used in preparing theterpolyamides preferably ranges from about 0.5 to 4 mole percent. Ifgreoater amounts are employed, the shrinkage and other physicalproperties of the terpolyarnides are noticeably changed.

The invention is further illustrated by the following examples.

PREFERRED EMBODIMENTS OF THE INVENTION Example 1 .Dry e-caprolactammonomer was added to 40% aqueous solution'of hexarnethylene diammoniumisophthalate (nylon 6IA salt) and this combination was added to normal50% aqueous solution of nylon 66 salt prior to beginning evaporation.The quantities of caprolactam and nylon 6IA salt were selected toproduce a 250-pound batch of terpolyamide containing 4 weight percent61A units, 0.5 weight percent 6 units and 95.5 weight percent 66 units.The salt mixture was charged to a stainless steel evaporator and heatedto 137 C. while maintaining a pressure within the evaporator of 13p.s.i.g. to obtain a solution. The solution is then transferred to astainless steel autoclave wherein the temperature is gradually increasedto 270 C. to effect polymerization. When the batch temperature reached200 C., sufficient 30% aqueous Ti0 was added to provide 0.3 weightpercent in the terpolymer. The molten terpolymer having a melt viscosityof 30 was extruded onto a casting wheel, solidified and cut into chips.The chips were subsequently charged to a spinning grid, melted at atemperature of 293 C., and pumped at a pressure of 4000 p.s.i.g. througha sand pack filter and 13-h0le spinneret to form a bundle of filamentswhich are quenched by a crosscurrent flow of air. After cooling, thefilament bundle placed in a rotating cell and light is impinged on theyarn and the reflected light was measured and a value determined. Thelower the value, the greater the dye depth and the diffusivity of thefiber. The standard deviation of the samples were determinedstatistically using 26 randomly was passed downward over a finish rollfor application Selected bobbins from the P 20 P P Chwmacyl of finishand wound onto a bobbin. The spun yarn com- Black W (Acid Black isformed y Complexing two posed of 13 filaments and having a nominal totaldenier atoms of Chromium with three moles of! of 123 was drawtwistedusing a conventional Whitin OH HO RG-4 drawtwister at a draw ratio of3.51 to 1 to yield I 40 denier yarn having /2 Z twist. NaOaS -N=NC Nylon66 yarns were also prepared for purposes of comparison according to theprocedure just described with the exception that the caprolactam andnylon 61A salt I were omitted. Properties of the yarns were determinedand NO: are given in Table I. The internal quality of the yarns It willbe observed from the data obtained in Examples was determined by theprocedure described above. 2 and 3 that the Chromacyl Black dye valuedetermined TABLE I Drawtwist performance, Internal Draw Elon- Breakingbreaks and quality, ratio Denier gatlon strength Tension wraps/lb.bks./lb.

Nylon 66 3. 23 39. 7 31. 5 188 4. 74 0. 107 1. 654 Terpolyamidea. 51 40.1 29. a 191 4. 76 0. 075 0. 417

The results in Table I show that the drawtwist performfor eachcomposition correlates closely with the percent ance and internalquality of the terpolyamide yarns, when diameter penetration value andthe time to half dye value compared to nylon 66 yanrs, are signficantlysuperior. determined therefor. Thus, for example, a composition In thefollowing examples the dye rate and dye pene- 0 having a lesser time tohalf dye value and a greater pertration of the yarns were alsodetermined. cent diameter pentration value, will also have a lesser Thedye rate of the yarns was measured by immersing Chromacyl Black dyedepth value. However, the detera skein of yarn weighing 6 grams into adye bath conmination of the time to half dye values and the percenttaining 0.2 gram Ortolan Bordeaux RR (Acid Red 296) diameter pentrationvalues are tedious analytical proceand 750 ml. of pure water. Thedyebath was maintained dures, whereas the determination of ChromacylBlack dye at a temperature of 89:L-1 C. Acid Red 296 is a chrodepthvalues is a relatively simple procedure. mium complex derived fromExample 2 9 A series of yarns, each having a different composition, Cwere prepared according to the procedure of Example 1, with theexception that a 26-hole spinneret was employed slozNflo rather than a13-hole spinneret and the yarn was drawn to a denier of 30. Thecomposition of each yarn in the series and is substantially equivalentto Perlon Fast Red 3B5 15 glven m Table The dye Penal-anon, dye rate andwhich is no longer produced. A Beckman DK2A record- Black depth valuesof e yam were ing spectophotometer measures and records the concendetermined follow1ng the procedures described above and tration of dyein the bath as a function of time. From the drawtwlst Performance ofeach yam was observedthese data the time required for the yarn sample toreach The results are glven m Table half of its saturation value wascalculated.

The dye penetration of the yarns was measured by immersing a skein ofyarn weighing 5 grams into a dyebath containing 0.025 gram of ColorIndex Number Acid TABLE H Blue 113 (Pontacyl Fast Blue 5 R) and 1000 ml.of pure Y W D W1 t cgft'mkagter rerce nt TI water. The dy ebath wasmaintained at a temperature beg'g gt gf y 333335, g ,gg figgi to :3tween 80 '90 C. Pontacyl Fast Blue 5R has the structure 66 6m 6 hm 5 0 wgt n 11 1 1; 1 1 7 -8- 21:22: as; ea 0. 028 118-30. 1 72. 3 1. 5 o. 084227-33. 7 53. 3

After 30 minutes the yarn sample was dried, cross-sectioned and thepercent radial penetration measured microscopically.

According to an alternative procedure for measuring the dye penetrationand dye rate of yarns a skein of yarn, after scouring to remove the spinfinish, was dyed in Chromocyl Black w solution containing 0.25 weightpercent dye, 0.5 weight percent ammonia and 40 ml. of pure water pergram of yarn. When the yarn sample was immersed in the dyebath, thedyebath temperature was 70 F. The bath was increased to 190 F. in 10minutes and then to 212 F. in 10' additional minutes. Dyeing wascontinued for minutes at 212 F. The yarn sample was then rinsed, driedand the reflectance thereof measured using a refiextometer as follows:the yarn sample was Example 3 A series of yarns, each having a dilferentcomposition, were prepared according to the procedure of Example 1 andtested in the same manner as described in Example 2. The results ofthese tests are given in Table III.

draw ratio required to produce a given yarn elongation (denier) ishigher than that required for the other yarns.

What is claimed is: 1. A linear synthetic terpolyamide having a polymerchain consisting essentially of 93 to 99.25 weight percent or randomlyrepeating units of the structure 0.25 to 3 weight percent of randomlyrepeating units of the structure and 0.50 to 4 weight percent ofrandomly repeating units of the structure TABLE III Yarn composition,Drawtwist Colormaster weight percent perform- Internal dye depth,Diameter Time to ance, quality Draw Chromaeyl penetration, half dye, 6661A 6 41A 21A breaks/lb. breaks/l ratio black percent secondsUnrunnable. Estimated.

The results in Table III further demonstrate that yarn 0 0 prepared fromthe terpolyamides of the present invention E ,E have excellentdrawtwlstperformance, mternal quality and units, 4 weight percent dyecharacterlstlcs. Surpnsmgly, yarns composed of 6 6 6-4IA and -6662IAdyed darker with the Chromoacyl 20 Black dye than the yarns composed of66, 66-61A or 66- NH(CHz) i3 6-6IA even though the draw ratio oftheyarns was conunits and 2 Weight percent slderably higher. Moreover, anincrease in spinning production is realized in spinning yarns composedof 66-6- E; E 41A and 66-6-2TA Since at constant spinning speeds the 25NH(CH2)|1NH units in which n is an integer from 2 to 6.

7. The nylon filament of claim 6, wherein n is 6.

8. The nylon filament of claim 7, wherein n is 4.

9. The nylon filament of claim 7, wherein n is 2.

References Cited UNITED STATES PATENTS 2,071,253 2/1937 Carothers 260-782,252,555 8/ 1941 Carothers 260-78 2,252,557 8/1941 Czerwin 260783,310,534 3/1967 Brignac 26078 3,322,731 5/1967 Cook et al. 260-783,383,369 5/1968 Ridgway 260-78 3,399,108 8/1968 Olson 161173 3,454,5367/1969 Schade et al. 260-78 FOREIGN PATENTS 1,025,098 4/1966 GreatBritain.

1,114,541 5 1968 Great Britain.

WILLIAM H. SHORT, Primary Examiner H. SCHAIN, Assistant Examiner US. Cl.X.R. 8-55; 57-14'0

